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   Author  Topic: inequalities  (Read 412 times)
Radiohead_man
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inequalities  
« on: Dec 14th, 2004, 8:28am »
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Put the numbers
x = (a + b)(c + d)
y = (a + c)(b + d)
z = (a + d)(b + c)
in ascending order, if a < b < c < d.
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JocK
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Re: inequalities  
« Reply #1 on: Dec 14th, 2004, 12:41pm »
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::
a+b < a+c < a+d
a+b < a+c < b+c
c+d > b+d > a+d
c+d > b+d > b+c
 
now think about rectangles with circumference twice a+b+c+d :  the more elongated the rectangle, the smaller the area  
  [bigto]  x < y < z
::
« Last Edit: Dec 14th, 2004, 12:44pm by JocK » IP Logged

solving abstract problems is like sex: it may occasionally have some practical use, but that is not why we do it.

xy - y = x5 - y4 - y3 = 20; x>0, y>0.
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